It is well known that many types of industrial machinery require rotary unions to allow for the transfer of fluid from a stationary to a rotating element. Typically, these fluids consist of lubricants, hydraulic fluid, cooling agents, or combinations thereof. Previously known rotary unions have typically utilized antifriction bearings for support and face seals to prevent leakage. However, it has been found that both antifriction bearings and face seals have been of a limited life duration, especially in operating environments of high pressure and speed. Moreover, it has particularly been found that severe vibrations encountered in stamping press operations also shorten the life expectancy of the prior art rotary unions. Indeed, the invention herein is particularly adapted for implementation in such stamping press operations which have previously contributed to the shortened life expectancies of the prior art rotary unions.
The prior art has taught the common usage of cartridge-type in-the-shaft rotary unions to allow passage of the fluids described above. Accordingly, the rotating shaft of the machinery to which the rotary union is affixed is specifically bored and housed to receive the prior art rotary unions. It is most desirable that a rotary union, absent antifriction bearings and face seals, be provided in such a configuration as to be received in the same bores and housings.